GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
GRE Prep Club Team Member
Joined: 20 Feb 2017
Posts: 2508
Given Kudos: 1053
GPA: 3.39
Lake A has a duck population of 30 females and 36 males. Lake B’s duck
[#permalink]
04 May 2021, 03:25
04 May 2021, 03:25
Expert Reply
2
Bookmarks
00:00
Question Stats:
90% (01:47) correct
10% (01:35) wrong based on 10 sessions
Hide Show timer Statistics
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?
A. 144
B. 105
C. 78
D. 51
E. 36
A. 144
B. 105
C. 78
D. 51
E. 36
Re: Lake A has a duck population of 30 females and 36 males. Lake B’s duck
[#permalink]
04 May 2021, 07:16
04 May 2021, 07:16
1
Solution:-
The ratio of duck's population in lake A=30/36=5/6
Thus, the ratio in lake B=5/6
5x+6x+6=Total population of the duck
11x+6=y
Now, we need a number when subtracted from 6 gives a integer divisible by 11
Only 105 works.
IMO B
The ratio of duck's population in lake A=30/36=5/6
Thus, the ratio in lake B=5/6
5x+6x+6=Total population of the duck
11x+6=y
Now, we need a number when subtracted from 6 gives a integer divisible by 11
Only 105 works.
IMO B
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
Re: Lake A has a duck population of 30 females and 36 males. Lake B’s duck
[#permalink]
04 May 2021, 08:23
04 May 2021, 08:23
1
GeminiHeat wrote:
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?
A. 144
B. 105
C. 78
D. 51
E. 36
A. 144
B. 105
C. 78
D. 51
E. 36
In Lake B:
\(\frac{F}{M} = \frac{5x}{6x}\)
After adding the female ducks:
\(\frac{F}{M} = \frac{5x+6}{6x}\)
Total Ducks in Lake B = \(11x + 6\)
So, our answer must be a number which is divisible by 11 when 6 is subtracted from it!
Hence, option B
